biological standardization of chenopodium album allergen extract

Conditions: Allergy to Chenopodium Album

Summary: the objective of this study is to determine the biologic activity of a chenopodium album allergen extract in histamine equivalent prick (hep) units, in order to be used as in-house reference preparation (ihrp).

this is an open, unblinded and non-randomized biological assay. the study design is a slight modification of the recommendations proposed by the nordic guidelines. four concentrations of chenopodium album allergen extract, together with a positive and negative control, using 10 mg/ml histamine dihydrochloride solution and a glycerinated phenol saline solution, respectively, will be tested in every patient in duplicate on the volar surface of the forearm.

Eligibility criteria:
inclusion criteria: * subject has provided written informed consent, appropriately signed and dated by the subject (or legal representative, if applicable). * subject can be male or female of any race and ethnic group. * age \> and =18 years and \< and =60 years at the study inclusion day. * positive skin prick test with a standardized commercially available preparation of chenopodium album allergen extract. * a positive test for specific ige to chenopodium album (cap-rast major or equal to 2). * allergic symptoms during the pollen season of chenopodium album. * medical history positive allergy inhalation (rhinitis and /or rhinoconjunctivitis and/or asthma) from chenopodium album. exclusion criteria: * immunotherapy in the past 5 years with an allergen preparation known to interfere with the allergen to be tested. * use of drugs that may interfere with the skin reactions (e.g., antihistamines). * treatment with any of the following medications: tricyclic or tetracyclic o imaos antidepressants,b-blockers or chronic use of corticosteroids or oral or use of corticoids both via oral or parenteral, in repeated patterns and intermittent (\> 10 mg/día de prednisone or equivalent). * women who are pregnant or period of breastfeeding and women with a pregnancy test positive during the visit 2, prior to the prick test. * dermographism affecting the skin area at the test site at either study visit. * atopic dermatitis affecting the skin area at the test site at either study visit. * urticaria affecting the skin area at the test site at either study visit. * diseases of the immune system relevant clinically, both autoimmune and immunodeficiencies. * serious diseases not controlled that may increase the risk for the safety of the subjects involved in this study, including, but not limited to the following: heart failure, uncontrolled or severe respiratory diseases, endocrine diseases, clinically relevant kidney or liver diseases or hematological diseases. * participation in any other clinical trial within 30 days (or 5 times the biological half-life of the research of the study product, whichever is longer) prior to the inclusion of the subject in this clinical trial. * patients with diseases or conditions that limit the use of adrenaline (heart disease, severe hypertension, ..) * severe psychiatric, psychological or neurological disorders * abuse of alcohol, drugs or medicines in the previous year.

Keywords: standardization immunotherapy skin prick test